Image sensor and image processing system

ABSTRACT

The present technology is to provide an image sensor capable of enhancing the security of biometric information and lowering the risk of information leakage. 
     An image sensor  10  includes: a biometric information acquisition unit  102  that acquires biometric information; a storage unit  14  that stores reference information to be compared with the biometric information; and a biometric authentication unit  104  that performs biometric authentication by comparing the biometric information with the reference information. The image sensor  10  further includes an encryption processing unit  105  that encrypts biometric authentication information that authenticates a living organism.

TECHNICAL FIELD

The present technology relates to an image sensor and an imageprocessing system. More particularly, the present technology relates toan image sensor and an image processing system that perform biometricauthentication.

BACKGROUND ART

Complementary metal oxide semiconductor (CMOS) image sensors, chargecoupled device (CCD) image sensors, and the like are used these days assemiconductor imaging elements (image sensors) that convert lightentering from lenses of industrial devices such as mobile terminals anddigital cameras into electrical signals, for example. With such imagesensors, biometric authentication using a small-size sensor mounted on amobile terminal is being considered in the identity confirmationrequired in financial transactions such as mobile banking, for example.

In a case where this biometric authentication is performed, biometricinformation about the users needs to be protected, and a high-securitybiometric authentication process is required. Therefore, Patent Document1 suggests a mobile terminal that transmits biometric image data imagedby an imaging means to an image processing server, receives biometricinformation generated from the biometric image data from the imageprocessing server, and performs a matching process related to biometricauthentication using an IC chip, for example.

CITATION LIST Patent Document

-   Patent Document 1: Japanese Patent Application Laid-Open No.    2011-165102

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

According to the technology disclosed in Patent Document 1, however,biometric information is transmitted to an image processing serveroutside a mobile terminal. Therefore, even if the biometric informationis encrypted, the biometric information might be monitored between themobile terminal and the image processing server, and there is always arisk of poor security of biometric information.

The present technology has been made in view of such circumstances, andaims to provide an image sensor capable of enhancing the security ofbiometric information and lowering the risk of information leakage.

Solutions to Problems

To solve the above problem, an image sensor as an example of the presenttechnology includes: a biometric information acquisition unit thatacquires biometric information; a storage unit that stores referenceinformation to be compared with the biometric information; and abiometric authentication unit that performs biometric authentication bycomparing the biometric information with the reference information.

Further, an image processing system as an example of the presenttechnology includes: an image sensor including: a biometric informationacquisition unit that acquires biometric information; a storage unitthat stores reference information to be compared with the biometricinformation; a biometric authentication unit that performs biometricauthentication by comparing the biometric information with the referenceinformation; an encryption processing unit that encrypts biometricauthentication information that authenticates a living organism; and anencrypted information output unit that outputs encrypted informationobtained by encrypting the biometric authentication information; and aprocessor that performs processing in accordance with the encryptedinformation output from the image sensor.

Effects of the Invention

According to the present technology, it is possible to provide an imagesensor capable of enhancing the security of biometric information andlowering the risk of information leakage. Note that effects of thepresent technology are not limited to the above effect, and may includeany of the effects described in the present disclosure.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing an example configuration of an imagesensor according to the present technology.

FIG. 2 is a block diagram showing an example configuration of an imageprocessing system according to the present technology.

FIG. 3 is a flowchart for explaining a biometric authentication processusing the image sensor according to the present technology.

FIG. 4 is a block diagram showing an example configuration of an imagesensor according to a conventional technology.

FIG. 5 is a block diagram showing an example configuration of an imageprocessing system according to the conventional technology.

FIG. 6 is a flowchart for explaining a biometric authentication processusing the image sensor according to the conventional technology.

FIG. 7 is a block diagram showing a first example stack in an imagesensor according to the present technology.

FIG. 8 is a block diagram showing a second example stack in an imagesensor according to the present technology.

MODE FOR CARRYING OUT THE INVENTION

The following is a description of preferred embodiments for carrying outthe present technology, with reference to the accompanying drawings.Note that the embodiments described below are typical examples ofembodiments of the present technology, and do not narrow theinterpretation of the scope of the present technology. Explanation willbe made in the following order.

1. Example Configuration of an Image Sensor According to the PresentTechnology

2. Example Configuration of an Image Processing System According to thePresent Technology

3. Biometric Authentication Process Using the Image Sensor According tothe Present Technology

4. Example Configuration of an Image Sensor According to a ConventionalTechnology

5. Example Configuration of an Image Processing System According to theConventional Technology

6. Biometric Authentication Process Using the Image Sensor According tothe Conventional Technology

7. First Example Stack in an Image Sensor According to the PresentTechnology

8. Second Example Stack in an Image Sensor According to the PresentTechnology

1. Example Configuration of an Image Sensor According to the PresentTechnology

FIG. 1 is a block diagram showing an example configuration of an imagesensor according to an embodiment of the present technology. An imagesensor 10 is a semiconductor imaging element that converts lightentering from a lens of an industrial device such as a mobile terminalor a digital camera into an electrical signal. The image sensor 10 maybe a complementary metal oxide semiconductor (CMOS) image sensor, acharge coupled device (CCD) image sensor, or the like, for example. Notethat image sensors according to the present technology are not limitedto this embodiment.

The image sensor 10 is capable of performing a biometric authenticationprocess therein, and includes a sensor unit 11 that photoelectricallyconverts light from the object into an electrical signal, an informationprocessing unit 12, an information output unit 13, and a nonvolatilememory 14 as a storage unit. The image sensor 10 also includes aregister interface 15 that transmits and receives setting values to andfrom the outside.

Here, “the outside” may be a recording medium storing image informationgenerated by the image sensor, a network for transmitting the imageinformation, a main processor that processes the image information, themain body of an imaging apparatus such as a digital camera, a personalcomputer (PC), a mobile terminal, a game machine, a noncontact-type ICcard such as FeliCa (registered trademark), a USB memory, or the like.

The information processing unit 12 processes acquired information asnecessary, and includes an image information acquisition unit 101, abiometric information acquisition unit 102, a living organismdetermination unit 103, a biometric authentication unit 104, and anencryption processing unit 105.

The image information acquisition unit 101 performs analog-to-digitalconversion (A/D conversion) to convert an electrical signalphotoelectrically converted by the sensor unit 11 from an analog signalto a digital signal, in accordance with light from the object imaged bya user. By doing so, the image information acquisition unit 101 acquiresimage information.

The biometric information acquisition unit 102 performs A/D conversionon the electrical signal photoelectrically converted by the sensor unit11 in accordance with the light of the object imaged to performbiometric authentication on the user. By doing so, the biometricinformation acquisition unit 102 acquires biometric information. Here,“biometric information” is information indicating features of a humanbody, such as an iris, a fingerprint, a vein, a face, a handprint, avoiceprint, a pulse wave, and a retina, for example.

The living organism determination unit 103 determines whether or not theacquired biometric information can authenticate the user.

The biometric authentication unit 104 compares the biometric informationdetermined to be able to authenticate the user with the referenceinformation stored in the nonvolatile memory 14, to determine whether ornot the user has a right to usage.

The encryption processing unit 105 generates encrypted information byencrypting the authenticated biometric authentication informationindicating that the user has a right to usage, and transmits theencrypted information to the information output unit 13.

The information output unit 13 outputs the information received from theinformation processing unit 12 to the outside, and includes an outputswitch unit 106 and an image information output unit 107.

The output switch unit 106 switches which information is to be output tothe outside, in accordance with the type of the information input fromthe information processing unit 12. In other words, the output switchunit 106 serves as a switch that switches output destinations. As theimage sensor 10 includes the output switch unit 106, it is possible forthe user to select whether to output the image information describedbelow or the encrypted information.

In a case where image information is selected as the information to beoutput through the output switch unit 106, the image information outputunit 107 receives image information captured by the user and outputs theimage information to the outside.

The nonvolatile memory 14 serves as a storage unit that holds the storedcontent without a power supply, and can store beforehand the referenceinformation to be compared with biometric information acquired from theobject. In this manner, the nonvolatile memory 14 can hold the referenceinformation, regardless of whether there is a power supply. Thus, theimage sensor 10 can perform a biometric authentication process bycomparing the acquired biometric information with the referenceinformation.

The register interface 15 transmits and receives setting values forexecuting the respective functions of the living organism determinationunit 103, the biometric authentication unit 104, the encryptionprocessing unit 105, and the nonvolatile memory 14. The registerinterface 15 also serves as an encrypted information output unit thatacquires the encrypted information generated by the encryptionprocessing unit 105 and transmits the encrypted information to a mainprocessor 20 in a case where outputting the encrypted information isselected at the output switch unit 106. Here, the image informationoutput unit 107 is an interface that outputs unencrypted imageinformation to the outside, and the register interface 15 is aninterface that outputs encrypted information. Therefore, the output bandof the image information output unit 107 is wider than the output bandof the register interface 15, which also serves as an encryptedinformation output unit.

Note that although the image sensor 10 of this embodiment includes theimage information acquisition unit 101, the output switch unit 106, andthe image information output unit 107, and is capable of outputtingnormal captured image information, an image sensor of the presenttechnology does not need to include an image information acquisitionunit, an output switch unit, and an image information output unit, aslong as the image sensor can perform a biometric authentication processtherein.

2. Configuration of an Image Processing System

According to the Present Technology

FIG. 2 is a block diagram showing an example configuration of an imageprocessing system according to an embodiment of the present technology.An image processing system 200 is a system that can be used for a mobileterminal, a digital camera, a video camera, or the like, for example,and performs a development process. The image processing system 200includes the image sensor 10 and the main processor 20.

Further, in FIG. 2, bold lines in the image processing system 200indicate a flow of information, thin lines indicate a flow oftransmission and reception of setting values, and dashed lines indicatea flow of image information in a case where the image information is tobe output. Note that image processing systems according to the presenttechnology are not limited to this embodiment.

The main processor 20 receives, from the image sensor 10, imageinformation or encrypted information subjected to information processingin accordance with light from an object 21, and performs a developmentprocess. The main processor 20 includes a CPU 201, a register interface202, an image information input unit 203, and a development processingunit 204.

The CPU 201 transmits a control signal for executing the respectivefunctions of the image sensor 10 to the register interface 202 and thelike, and transmits a command signal for executing the respectivefunctions of the main processor 20 to each component.

The register interface 202 transmits the control signal from the CPU 201to the register interface 15 of the image sensor 10.

In response to the command signal from the CPU 201, the imageinformation input unit 203 inputs image information output from theimage sensor 10.

In response to the command signal from the CPU 201, the developmentprocessing unit 204 performs a development process on an output image,in accordance with the image information received from the imageinformation input unit 203.

3. Biometric Authentication Process Using the Image Sensor According tothe Present Technology

FIG. 3 is a flowchart for explaining a biometric authentication processusing the image sensor according to the present technology. Referring toFIG. 3, the respective procedures in a biometric authentication processof this embodiment are now described.

First, in step S301, when the CPU 201 of the main processor 20 transmitsa command signal indicating a request for a transaction such assettlement or the like to the image sensor 10 via the register interface202 in accordance with a user operation, a series of processes isstarted.

In step S302, the encryption processing unit 105 of the image sensor 10,which has received the command signal indicating the transactionrequest, and the CPU 201 of the main processor 20 start mutualauthentication as to whether or not both sides have a right of access toeach other.

In step S303, the encryption processing unit 105 verifies the public keyof the main processor 20, and the CPU 201 of the main processor 20verifies the public key of the image sensor 10, to determine whether ornot both public keys are authentic.

If the determination result is YES in step S303, or if it is confirmedthat both public keys are authentic, the process moves on to step S304.If the determination result is NO in step S303, or if it cannot beconfirmed that both public keys are authentic, the process moves on tostep S305. Since the operation was performed by a person who is notauthorized to conduct a transaction, it is determined that thetransaction has failed, and the process comes to an end.

In step S304, the encryption processing unit 105 performs Diffie-Hellmankey exchange (DH key exchange), to generate an Advanced EncryptionStandard (AES) key, for example. After an AES key is generated by theencryption processing unit 105, the process moves on to step S306.

In step S306, the sensor unit 11 of the image sensor 10 images an irisor the like of the object 21, for example, to obtain biometricinformation about the object 21. After an iris or the like is imaged,the process moves on to step S307.

In step S307, the sensor unit 11 determines whether or not the exposureis appropriate. If the determination result is YES in step S307, or ifthe exposure is appropriate, the process moves on to step S308. If thedetermination result is NO in step S307, or if the exposure is notappropriate, the process moves on to step S309, and the sensor unit 11calculates exposure settings, to achieve appropriate exposure. Afterappropriate exposure settings are calculated, the process returns tostep S306, and the sensor unit 11 again images an iris or the like ofthe object 21.

Next, in step S308, the living organism determination unit 103determines whether or not the object 21 is a living organism. Morespecifically, in the case of iris authentication, the living organismdetermination unit 103 performs the determination by measuring thedilation/contraction of the pupil, the reflectance of the object 21, andthe like, for example. Thus, it is possible to prevent access by animposter using a photograph, an image, or the like of the object 21.

If the determination result is YES in step S308, or if the object 21 isdetermined to be a living organism, the process moves on to step S310.If the determination result is NO in step S308, or if the object 21 isdetermined not to be a living organism, the process moves on to stepS305. Since the operation was performed by a person who is notauthorized to conduct a transaction, it is determined that thetransaction has failed, and the process comes to an end.

In step S310, the biometric authentication unit 104 determines whetheror not the biometric information acquired from the imaged object 21matches the reference information that is about a person having anaccess right and is stored beforehand in the nonvolatile memory 14. Inother words, the image sensor 10 of this embodiment performs so-calledone-to-N(N being a natural number) comparison between the one piece ofreference information stored in advance and biometric informationacquired by the image sensor 10, to determine whether or not theacquired biometric information is biometric information about a specificuser having an access right.

If the determination result is YES in step S310, or if the acquiredbiometric information matches the reference information, the processmoves on to step S311, and transaction processing such as settlement orthe like with the user is started. If the determination result is NO instep S310, or if the acquired biometric information does not match thereference information, the process moves on to step S305. Since theoperation was performed by a person who is not authorized to conduct atransaction, it is determined that the transaction has failed, and theprocess comes to an end.

In step S311, the encryption processing unit 105 generates encryptedinformation by encrypting the biometric authentication information thathas authenticated the living organism. The generated encryptedinformation is input to the output switch unit 106. After outputting theencrypted information is selected, the encrypted information istransmitted to the register interface 202 of the main processor 20 bythe register interface 15. After that, the CPU 201 having received theencrypted information from the register interface 202 decrypts theencrypted information, and starts transaction processing such assettlement with the user.

An image sensor according to the present technology is an image sensorthat performs encryption inside an image sensor using a conventionalcommon key encryption technique as an example encryption technique, andoutputs the encrypted information to the outside. However, encryptionaccording to the present technology is not limited to the common keyencryption technique. Here, the “common key encryption technique” refersto an encryption technique using a key common in encryption anddecryption.

As described above, the image sensor 10 of this embodiment performs abiometric authentication process therein. Accordingly, there is no needto output RAW data of biometric information to the outside. Thus, thesecurity of the biometric information can be enhanced, and the risk ofinformation leakage can be lowered.

Furthermore, in a case where encrypted information is output from theimage sensor 10 to the outside while image information is not output asin this embodiment, there is no need to prepare a large-capacityinterface such as cables for outputting image information, and thus, themodule design can be made simpler. In a case where a high-speedtransmission line having a bandwidth on the order of GHz like an imagesensor is designed as an ultra-thin module, it will be difficult tomaintain high quality, because wires such as a plurality of cables arefolded in a narrow area. In view of this, the large-capacity interfacefor outputting images is made unnecessary, so that the complexity ofmodule design can be reduced.

4. Example Configuration of an Image Sensor According to a ConventionalTechnology

FIG. 4 is a block diagram showing an example configuration of an imagesensor according to a conventional technology. Like the image sensor 10according to the present technology, an image sensor 40 may be a CMOSimage sensor, a CCD image sensor, or the like.

The image sensor 40 performs a biometric authentication process outside,and includes a sensor unit 41, an information processing unit 42, and aninformation output unit 43. The image sensor 40 also includes a registerinterface 44 that transmits and receives signals to and from theoutside. The register interface 44 transmits and receives a controlsignal for an encryption processing unit 105 to perform processing.

The information processing unit 42 performs a process of encryptingacquired biometric information, and includes an information acquisitionunit 401 and an encryption processing unit 402.

The information acquisition unit 401 performs A/D conversion on anelectrical signal photoelectrically converted by the sensor unit 11 inaccordance with light of the object imaged to perform biometricauthentication on the user. By doing so, the information acquisitionunit 401 acquires biometric information. The information acquisitionunit 401 also performs A/D conversion on the electrical signalphotoelectrically converted by the sensor unit 11 in accordance with thelight of the subject imaged by the user, and thus, acquires imageinformation.

The encryption processing unit 402 generates encrypted information byencrypting the acquired biometric information, and transmits theencrypted information to the information output unit 43.

The information output unit 43 receives the encrypted information orimage information from the encryption processing unit 402, and outputsthe received information to the outside.

5. Example Configuration of an Image Processing System According to theConventional Technology

FIG. 5 is a block diagram showing an example configuration of an imageprocessing system according to the conventional technology. An imageprocessing system 500 is a system that can be used for a mobileterminal, a digital camera, a video camera, or the like, for example,and performs a development process. The image processing system 500includes the image sensor 40 and a main processor 50. Further, in FIG.5, bold lines in the image processing system 500 indicate a flow ofinformation, and thin lines indicate a flow of transmission andreception of setting values.

The main processor 50 receives, from the image sensor 40, encryptedinformation or image information subjected to information processing inaccordance with light from an object 51, and performs a biometricauthentication process or a development process. The main processor 50includes a CPU 501, a register interface 502, an information input unit503, a development processing unit 504, and a biometric authenticationunit 505.

The CPU 501 transmits a control signal for executing the respectivefunctions of the image sensor 40 to the register interface 502 and thelike, and transmits a command signal for executing the respectivefunctions of the main processor 50 to each component. The CPU 501 alsoserves as an encryption processing unit that encrypts biometricauthentication information subjected to a biometric authenticationprocess.

The register interface 502 transmits the control signal from the CPU 501to the register interface 44 of the image sensor 40.

In response to the command signal from the CPU 501, the informationinput unit 503 inputs encrypted information or image information outputfrom the image sensor 40.

In response to the command signal from the CPU 501, the developmentprocessing unit 504 performs a development process on an output image,in accordance with the image information received from the informationinput unit 503.

The biometric authentication unit 505 compares the biometric informationdetermined to be able to authenticate the user with referenceinformation acquired from the outside, to determine whether or not theuser has a right to usage. Note that the biometric authentication unit505 also serves as a living organism determination unit that determineswhether or not encrypted biometric information can authenticate theuser.

6. Biometric Authentication Process Using the Image Sensor According tothe Conventional Technology

FIG. 6 is a flowchart for explaining a biometric authentication processusing the image sensor according to the conventional technology.Referring to FIG. 6, the respective procedures in a biometricauthentication process according to the conventional technology are nowdescribed.

First, in step S601, when the CPU 501 of the main processor 50 transmitsa command signal indicating a request for a transaction such assettlement or the like to the image sensor 40 via the register interface502 in accordance with a user operation, a series of processes isstarted.

In step S602, the encryption processing unit 402 of the image sensor 40,which has received the command signal indicating the transactionrequest, and the CPU 501 of the main processor 50 start mutualauthentication as to whether or not both sides have a right of access toeach other.

In step S603, the encryption processing unit 402 verifies the public keyof the main processor 50, and the CPU 501 of the main processor 50verifies the public key of the image sensor 40, to determine whether ornot both public keys are authentic.

If the determination result is YES in step S603, or if it is confirmedthat both public keys are authentic, the process moves on to step S604.If the determination result is NO in step S603, or if it cannot beconfirmed that both public keys are authentic, the process moves on tostep S605. Since the operation was performed by a person who is notauthorized to conduct a transaction, the encryption is suspended, andthe process comes to an end.

In step S604, the encryption processing unit 402 generates an AdvancedEncryption Standard (AES) key, and performs Diffie-Hellman key exchange(DH key exchange), for example. After an AES key is generated by theencryption processing unit 402, the process moves on to step S606.

In step S606, the sensor unit 41 of the image sensor 40 images an irisor the like of the object 51, for example, to obtain biometricinformation about the object 51. After an iris or the like is imaged,the process moves on to step S607.

In step S607, the sensor unit 41 determines whether or not the exposureis appropriate. If the determination result is YES in step S607, or ifthe exposure is appropriate, the process moves on to step S608. If thedetermination result is NO in step S607, or if the exposure is notappropriate, the process moves on to step S609, and the sensor unit 41calculates exposure settings, to achieve appropriate exposure. Afterappropriate exposure settings are calculated, the process returns tostep S606, and the sensor unit 41 again images an iris or the like ofthe object 51.

Next, in step S608, the CPU 501 starts AES encryption of the acquiredbiometric information. After that, the biometric authentication unit (aliving organism determination unit) 505 of the main processor 50compares the biometric information with the reference information storedin a server or the like, and determines whether or not the biometricinformation matches the reference information. In a case where thebiometric information matches the reference information, the CPU 501starts transaction processing such as settlement with the user.

As described above, in a case where a biometric authentication processusing the image sensor 40 according to a conventional technology isperformed, the biometric authentication process is performed in the mainprocessor 50 outside the image sensor 40. Therefore, it is necessary tooutput the RAW data of biometric information from the image sensor 40 tothe main processor 50. Because of this, even if the RAW data ofbiometric information is encrypted, there is a possibility that theencrypted data is decrypted, and the information leaks. In such a case,security is far from perfect. To solve this problem, an image sensoraccording to the present technology enhances the security of biometricinformation by performing a biometric authentication process inside theimage sensor.

7. First Example Stack in an Image Sensor According to the PresentTechnology

FIG. 7 is a block diagram showing an example stack in a first embodimentof a stacked image sensor according to the present technology. Thestacked image sensor may be stacked CMOS image sensor, for example, butthe present technology is not limited to a stacked CMOS image sensor.Further, the CMOS image sensor may be of a back-illuminated type. Aback-illuminated CMOS image sensor has a structure in which pixels,circuits, and the like are formed on a silicon substrate, and thethickness of a silicon substrate on the back side of the image sensor isreduced to several micrometers so as to capture light.

As shown in FIG. 7, in a stacked image sensor 700 of this embodiment,two boards are stacked, as a signal processing board 702 is disposed onthe back side of a pixel board 701 provided with the sensor unit 11 thatphotoelectrically converts light from the object 21 into an electricalsignal. The information processing unit 12, the information output unit13, and the nonvolatile memory 14 shown in FIG. 1 are provided on thesignal processing board 702.

As in the image sensor 700 of this embodiment, a two-layer stackstructure is formed with the signal processing board 702 disposed on thepixel board 701. With this arrangement, biometric information cannot beeasily read or analyzed from outside, and thus, the security ofbiometric information can be enhanced.

8. Second Example Stack in an Image Sensor According to the PresentTechnology

FIG. 8 is a block diagram showing an example stack in a secondembodiment of a stacked image sensor according to the presenttechnology. As in FIG. 8, the stacked image sensor may be a stacked CMOSimage sensor, for example, but the present technology is not limited toa stacked CMOS image sensor.

As shown in FIG. 8, in a stacked image sensor 800 of this embodiment,three boards are stacked, as a signal processing board 802 is interposedbetween a pixel board 801 provided with the sensor unit 11 and a memoryboard 803. The information processing unit 12 and the information outputunit 13 are provided on the signal processing board 802. Meanwhile, thenonvolatile memory 14 is provided on the memory board 803.

As in the image sensor 800 of this embodiment, a three-layer stackstructure is formed with the pixel board 801 and the memory board 803covering the front surface and the back surface of the signal processingboard 802. With this arrangement, it is more difficult to read oranalyze biometric information from outside than with the two-layer stackstructure shown in FIG. 7, and thus, the security of biometricinformation can be further enhanced.

Note that embodiments of the present technology are not limited to theabove described embodiments, and various modifications may be made tothem without departing from the scope of the present technology. Forexample, it is possible to adopt a combination of all or some of theabove described plurality of embodiments. Specifically, an image sensoraccording to the present technology can be applied to a device thatdetermines whether or not the person scheduled to drive a vehicle suchas an automobile is authorized to drive the vehicle, a device thatperforms entry and exit management at an entrance/exit of a building,the unlocking function of a mobile terminal such as a smartphone, or thelike, for example.

The present technology may also be embodied in the configurationsdescribed below.

(1) An image sensor including: a biometric information acquisition unitthat acquires biometric information; a storage unit that storesreference information to be compared with the biometric information; anda biometric authentication unit that performs biometric authenticationby comparing the biometric information with the reference information.

(2) The image sensor according to (1), further including an encryptionprocessing unit that encrypts biometric authentication information thatauthenticates a living organism.

(3) The image sensor according to (2), further including an encryptedinformation output unit that outputs encrypted information obtained byencrypting the biometric authentication information.

(4) The image sensor according to (3), further including: an imageinformation acquisition unit that acquires image information; and animage information output unit that outputs the image information, inwhich an output band of the image information output unit is wider thanan output band of the encrypted information output unit.

(5) The image sensor according to (4), further including an outputswitch unit that selectively switches between the image information andthe encrypted information, and outputs the image information or theencrypted information.

(6) The image sensor according to (1), further including a biometricinformation determination unit that determines whether or not thebiometric information is information that can be compared with thereference information.

(7) The image sensor according to (1), in which the biometricinformation is iris information.

(8) The image sensor according to (1), in which the image sensor is of astacked type that has a pixel board and a signal processing boardstacked on each other, the biometric authentication unit being providedon the signal processing board.

(9) An image processing system including:

an image sensor including: a biometric information acquisition unit thatacquires biometric information; a storage unit that stores referenceinformation to be compared with the biometric information; a biometricauthentication unit that performs biometric authentication by comparingthe biometric information with the reference information; an encryptionprocessing unit that encrypts biometric authentication information thatauthenticates a living organism; and an encrypted information outputunit that outputs encrypted information obtained by encrypting thebiometric authentication information; and a processor that performsprocessing in accordance with the encrypted information output from theimage sensor.

REFERENCE SIGNS LIST

-   10, 40, 700, 800 Image sensor-   11, 41 Sensor unit-   12, 42 Information processing unit-   13 Information output unit-   14 Nonvolatile memory-   15, 44, 202, 502 Register interface-   20, 50 Main processor-   21, 51 Object-   43 Information output unit-   101 Image information acquisition unit-   102, 401 Biometric information acquisition unit-   103 Living organism determination unit-   104, 505 Biometric authentication unit-   105, 402 Encryption processing unit-   106 Output switch unit-   107 Image information output unit-   200, 500 Image processing system-   201, 501 CPU-   203, 503 Information input unit-   204, 504 Development processing unit-   701, 801 Pixel board-   702, 802 Signal processing board-   803 Memory board

1. An image sensor comprising: a biometric information acquisition unitthat acquires biometric information; a storage unit that storesreference information to be compared with the biometric information; anda biometric authentication unit that performs biometric authenticationby comparing the biometric information with the reference information.2. The image sensor according to claim 1, further comprising anencryption processing unit that encrypts biometric authenticationinformation that authenticates a living organism.
 3. The image sensoraccording to claim 2, further comprising an encrypted information outputunit that outputs encrypted information obtained by encrypting thebiometric authentication information.
 4. The image sensor according toclaim 3, further comprising: an image information acquisition unit thatacquires image information; and an image information output unit thatoutputs the image information, wherein an output band of the imageinformation output unit is wider than an output band of the encryptedinformation output unit.
 5. The image sensor according to claim 4,further comprising an output switch unit that selectively switchesbetween the image information and the encrypted information, and outputsthe image information or the encrypted information.
 6. The image sensoraccording to claim 1, further comprising a living organism determinationunit that determines whether or not the biometric information isinformation comparable with the reference information.
 7. The imagesensor according to claim 1, wherein the biometric information is irisinformation.
 8. The image sensor according to claim 1, wherein the imagesensor is of a stacked type that has a pixel board and a signalprocessing board stacked on each other, the biometric authenticationunit being provided on the signal processing board.
 9. An imageprocessing system comprising: an image sensor including: a biometricinformation acquisition unit that acquires biometric information; astorage unit that stores reference information to be compared with thebiometric information; a biometric authentication unit that performsbiometric authentication by comparing the biometric information with thereference information; an encryption processing unit that encryptsbiometric authentication information that authenticates a livingorganism; and an encrypted information output unit that outputsencrypted information obtained by encrypting the biometricauthentication information; and a processor that performs processing inaccordance with the encrypted information output from the image sensor.